Japan's chief cabinet secretary, one of the candidates vying for leadership of the main ruling party, says the consumption tax rate will need to be raised as the country's population is shrinking.

Suga Yoshihide made the remark in a commercial TV program on Thursday. He is one of three candidates seeking to win the leadership election of the Liberal Democratic Party on Monday. The winner is almost certain to become the next prime minister, replacing Abe Shinzo, who is stepping down for health reasons.